Earth device, plug-in breaker and distribution board

ABSTRACT

A grounding apparatus for a distribution device having a functional element and a grounding contact point includes a grounding rail having opposed end sections provided with a holding part for fitting the grounding rail to the functional element. An electrically conductive contact spring on each of the end sections extends outwardly beyond the holding part to make contact with the grounding contact point. A safety plug for use with the grounding apparatus includes an overvoltage protection device connected to a conductive contact tongue for contacting an electrical cable connected to the functional element. The overvoltage protection device has a grounding electrode and a conductive fitting in electrical contact with the grounding electrode is provided with an insulation-displacement terminal for connecting the safety plug to the grounding apparatus. A handling apparatus having a base body with a retaining groove is provided for installing the grounding apparatus to the distribution device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National application claiming priority toInternational Application No. PCT/EP02/03823 filed on Apr. 5, 2003,which claims priority to German Patent Application No. 101 20 720.4,filed on Apr. 27, 2001.

FIELD OF THE INVENTION

The invention relates to a grounding apparatus and a grounding devicefor a distribution device, such a main distributor for atelecommunications system, as well as a safety plug for use with agrounding apparatus according to the invention, and a distributiondevice. The invention also relates to a handling apparatus forinstallation of a grounding apparatus on a distribution device.

BACKGROUND OF THE INVENTION

In the case of distribution devices for telecommunications systems, suchas a main distributor, overvoltage protection is occasionally required.For this purpose, the cables which are connected to the distributiondevice are connected to respectively associated overvoltage protectiondevices via which an associated overvoltage current can be dissipated toground potential when an overvoltage is applied between the cableconductors that are connected to the distribution device. Since evermore connections have to be arranged in a relatively confined space, forcost and space reasons, it is necessary to provide grounding deviceswhich are matched to the reduced amount of space that is in consequenceavailable.

SUMMARY OF THE INVENTION

The invention provides a grounding apparatus and a grounding device fora distribution device, such as a main distributor for atelecommunications system, as well as a safety plug for use with agrounding apparatus and a grounding device, as well as a distributiondevice, thus allowing overvoltage protection to be provided simply andflexibly, in a space-saving manner. The invention also provides ahandling apparatus for installation of a grounding apparatus on adistribution device, in particular on a functional element of thedistribution device, by means of which the grounding apparatus can befitted securely and easily to the distribution device.

The grounding apparatus according to the invention for a distributiondevice, for example a main distributor for a telecommunications system,has an elongated grounding rail composed of electrically conductivematerial, in particular a metal material. The grounding rail ispreferably a single thin bent metal sheet, which may be reinforced bybeads. The grounding rail is provided on each of its end sections with aseparate holding part, that is to say a holding part which is not formedintegrally with the grounding rail, via which the grounding rail can befitted to a functional element of the distribution device. In this case,the expression functional element means a component of the distributiondevice to which a large number of incoming and outgoing electricalcables are connected, and via which the incoming and outgoing cables canbe electrically connected to one another by means of contacts, such asisolating contacts or switching contacts. In this case, incomingelectrical cables are those cables which are routed from outside thedistribution device, that is to say for example from a switching device,from another distribution device or from subscribers, to thedistribution device, and outgoing electrical cables are those cableswhich are connected to a jumper side of the functional element, and passonwards from there. The outgoing cables are in this case used as jumpercables, by means of which the desired communications link can beproduced by jumpering. The functional element is, for example, in theform of a connecting strip composed of plastic or in the form of aplastic part in the form of a panel, which has a connecting strip forconnection of cables, in particular of their cable cores, such as cablewires. Electrically conductive contact springs are provided on the endsections of the grounding rail and are connected to the rail for examplevia a clamping connection or a welded connection, in particular beingformed integrally with it, and extend past the holding part and areintended for making contact with a grounding contact point on thedistribution device.

The provision of separate holding parts which are arranged on thelongitudinal end sections of the ground rail makes it possible in asimple manner to vary the position of the grounding rail with respect tothe holding parts during the production of the grounding apparatus, andthus to match it to the necessary physical characteristics in thedistribution device, in particular to the arrangement of the functionalelements. It is thus possible in a simple manner, for example, toprovide holding parts each having identical receptacles, which areprovided at different points, for associated grounding rails. Theholding parts may be parts in the form of a block, for example cuboidblocks, in which cutouts are formed for insertion of the associatedgrounding rail. Two or more identical receptacles may also be providedat different positions on each holding part, so that the holding part isdesigned as such such that it can be used in a flexible manner.

The respective holding part is preferably in the form of an angled part,in order to save material, one of whose angled limbs is intended to befitted to the functional element, and whose other angled limb isintended for the fitting of the grounding rail. The angled form in thiscase still leaves sufficient physical play with respect to thearrangement of the grounding rail relative to the functional elementsince the choice of the length and alignment of the angled limbs for thegrounding rail allows a sufficiently large number of positions relativeto the functional element.

In order to more safely prevent cable currents from inadvertentlybreaking through to the grounding rail the holding parts are preferablyproduced from a nonconductive material, in particular from nonconductiveplastic. Plastic parts such as these can be provided in a simple andcost-effective manner as injection-molded parts. Since the functionalelements are themselves preferably composed of nonconductive plasticmaterial, plastic material is thus also advantageous for the holdingparts, since this reduces the risk of damage to the functional elementswhen the holding part is attached.

According to one embodiment of the invention, the holding parts eachhave a holding piece for fitting to the associated functional element,which holding piece extends essentially in a direction at right anglesto the longitudinal direction of the grounding rail. Furthermore, thecontact springs run essentially in the same direction as the holdingpieces, that is to say they extend essentially parallel to the holdingpieces away from the grounding rail. This results in a compact design,which has an advantageous effect on the space required for the entiredistribution device. Each holding piece may, for example, be formed byone limb of the angled holding part, for example in the form of anextension piece (in the form of a pin) on one angled limb, which canengage in a cutout that is formed on the functional element. A cutoutcan also be provided as a holding piece at the end on the free end ofthe angled limb, and a corresponding projection on the functionalelement can engage in this cutout. If a holding part which is in theform of a cuboid block is used, the holding piece may, for example, be aprojection in the form of a pin, which can engage in a correspondingcutout in the functional element, or may be a cutout whose openingpoints in said direction and in which an engagement piece which isprovided on the functional element can engage.

The grounding rail is advantageously arranged offset with respect to theholding pieces in a direction at right angles to its longitudinaldirection and at right angles to the direction in which the holdingpieces extend. In consequence, the grounding rail of a groundingapparatus which is fitted to the functional element is also arrangedcorrespondingly offset with respect to the functional element, so thatan operator still has sufficient access to the functional element inorder to make it possible to carry out jumpering work on the functionalelement without being impeded by the grounding apparatus. The contactsprings preferably extend parallel the holding pieces, running past theassociated holding parts; the contact springs are thus for this purposestart from the grounding rail and extend away in the direction of theholding pieces that are arranged offset. In the case of a grounding railwhich is formed integrally with the contact springs, the contact springsare for this purpose simply bent at an angle in the correspondingdirection.

The contact springs may, for example, extend internally, that is to saythey may extend past the mutually facing sides of the holding parts, inwhich case corresponding retaining openings may then need to be providedin the functional elements, through which the contact springs are passedto the grounding contact point. The contact springs advantageouslyextend past the holding parts on the outside, at the sides with respectto the longitudinal direction of the grounding rail, and can be spreadapart in a sprung manner outwards at the sides. They can thus makecontact in a sprung manner with a grounding contact point from theoutside at the sides. From the design point of view, this makes iteasier to provide an associated grounding contact point. Furthermore,there is no need to provide cutouts for the contact springs on thefunctional element, so that the functional element can be designed moreeffectively for accommodation of cable connections. The single-pointspring contact, which is also preferably achieved by the contact spring,with the grounding contact point results in only minor cable losses andcan likewise be designed in a simple manner.

Each contact spring is preferably provided at its free end with anengagement part, for example in the form of an engagement projection ora cutout, which can be engaged in a sprung manner with a correspondingengagement part on the functional element. In consequence, the contactspring is also at the same time used as a fixing element, whichpreferably fixes the grounding apparatus on the functional element byinteraction with the respective holding part. Since the contact springin this case runs past the holding part, immediately adjacent to it,this results in direct and thus short force profiles, so that it ispossible to provide components that are used having less strength, sothat the components are thus lighter and their costs are less.

The safety plug according to the invention for use with a groundingapparatus according to the invention has a contact tongue via whichelectrical cables which are laid in an associated functional element andare connected to it can be made contact with. For example, in case of afunctional element to which two or more incoming double core cables canbe connected, the safety plug according to the invention is designed,for example, with a double contact tongue, on which two separateconductor tracks are formed, with which the respective conductors in adouble core cable make contact when the safety plug is inserted into thefunctional element. According to the invention, the contact tongue isconnected to an overvoltage/overcurrent protection device. With regardto said example with double core cables, the overvoltage/overcurrentprotection device then, by way of example, has two electrodes which makecontact with the respective conductor track, and thus with theassociated cable core in the double core cable. According to theinvention, the overvoltage/overcurrent protection device has a groundingelectrode which has an attachment in the form of a rod, and via which anassociated overvoltage current can be dissipated when an overvoltage isapplied, for example between the two cores of a double core cable. Thesafety plug according to the invention, also has an electricallyconductive fitting, by means of which the safety plug can be fitted tothe grounding rail of the grounding device, and which makes electricalcontact with the grounding electrode. This has the advantage that thefitting is used as both a mechanical connection and an electricalconnection between the safety plug and the grounding apparatus.According to the invention, in order to produce this mechanical andelectrical contact, the fitting has: an insulation-displacementterminal, by means of which the fitting is clamped to the attachment,which is in the form of a rod, on the grounding electrode, and anattachment part for attaching the fitting to the grounding rail.

The insulation-displacement terminal represents a secure and simplemechanical and electrical connection between the safety plug and thegrounding apparatus. In contrast to a soldered joint, there is no riskof an insulation-displacement terminal becoming unsoldered if theconnection point were to become hot in the event of high overvoltagecurrents. Furthermore, an insulation-displacement terminal does notresult in any forces being exerted on the safety plug, which would haveto be absorbed by other external bearings, either. The remaining safetyplug components are thus preferably held on the fitting exclusively viathe insulation-displacement terminal connection, and the fittingaccordingly also preferably holds the safety plug on the groundingapparatus on its own.

The attachment part is preferably likewise in the form of a clampingpart which can be clamped to the grounding apparatus, that is to say toits grounding rail. This clamping part may likewise be aninsulation-displacement terminal, with the grounding rail for thispurpose being provided, for example, with corresponding pins, onto whichthis insulation-displacement terminal can be clamped. The clamping partis preferably provided with two such clamping limbs which can springapart elastically and between which the grounding rail can be clamped inplaces, in the direction transversely with respect to its longitudinaldirection. This clamping connection can be produced particularly easilyand thus at low cost, while its holding function is neverthelesssufficiently secure.

The grounding device according to the invention has a groundingapparatus according to the invention and at least one safety plugaccording to the invention, which is fitted to the grounding rail of thegrounding apparatus. The safety plugs are preferably fitted to thegrounding rail such that they can be replaced or interchanged, inparticular by means of a clamping apparatus, as described above, as anattachment part for the fitting, by means of which safety plugs can befitted to and detached from the grounding apparatus particularlyquickly.

The distribution device according to the invention has an elongatedretaining apparatus, one or more functional element or elements whichare held in the retaining apparatus, with the retaining apparatus beingdesigned such that the functional elements are stacked one on top of theother at a distance from one another, in particular being stackedlocated one above the other or horizontally, and can be held therein.Each functional element has an elongated contact section, that is to sayfor example a contact strip, with connecting points for connection ofincoming and outgoing electrical cables. The distribution device alsohas at least one grounding apparatus according to the invention, whosegrounding rail is arranged parallel to the elongated contact section ofthe associated functional element, and which is fitted by means of theassociated holding parts to longitudinal end sections of the functionalelement; the longitudinal element sections are in this case related tothe longitudinal direction of the contact section. The distributiondevice also has at least one safety plug according to the invention,which is fitted to the grounding rail such that its contact tongueextends in the direction of the functional element, in order to makecontact with the electrical cables associated with it.

The grounding process is completed by the contact springs of therespective grounding apparatus being electrically connected to therespectively associated grounding contact points, which are connected toground. For this purpose, the entire retaining apparatus is preferablysimply composed of conductive material, in particular of metal, with thecontact springs on the grounding rail of the grounding apparatus makingelectrical contact with a section of the retaining apparatus that isused as the grounding contact point, in order in this way to completethe grounding process. The retaining apparatus may, however, also beequipped with a separate grounding cable, which is electricallyconnected via respectively associated grounding contact points to thecontact springs on the grounding rail of the respective groundingapparatus.

According to one embodiment of the invention, the grounding rail of therespective grounding apparatus is arranged offset with respect to theassociated functional element in the direction along the retainingapparatus. In consequence, the access points to the connecting points ofthe respective functional element remain sufficiently accessible for anoperator.

According to a further embodiment of the invention, the connectingpoints are arranged along the elongated contact section of therespective functional element, and are subdivided into a row of firstconnecting points for incoming cables, and a row of second connectingpoints for outgoing cables. The grounding rail of the associatedgrounding apparatus is in this case arranged adjacent to the row ofsecond connecting points, on its side facing away from the row of firstconnecting points. In this arrangement, the space that is providedbetween the rows of first and second connecting points for jumpering isnot blocked by the grounding apparatus, and is thus convenientlyaccessible for an operator. Since the functional elements are arrangedone above the other or alongside one another in the retaining apparatus,this offsetting of the grounding rail is, however, chosen only to suchan extent that the grounding rail always still covers the row of firstconnecting points of the functional element arranged underneath it oralongside it, but not the free space which follows once again underneathit or alongside it, in particular not the subsequent row of secondconnecting points of this functional element. This is because this freespace is intended to be accessible for the insertion of safety plugs,and the respective rows of second connecting points (jumper side) mustbe accessible for jumpering.

According to one embodiment of the invention, the retaining apparatus isdesigned in the form of an elongated, electrically conductive retainingtrough with a trough base and two trough limbs. The retaining trough ispreferably composed of metal material. Elongated retaining tongues areformed in the trough limbs, and their longitudinal directions extendparallel to the direction in which the limbs extend, and hence at rightangles to the longitudinal direction of the trough. Each functionalelement is inserted between the retaining tongues, that is to saybetween each two retaining tongues, with the contact springs of thegrounding apparatus which is fitted to the respective functional elementmaking contact in a sprung manner with the retaining tongues in order toproduce an electrical contact.

The contact springs produce a secure single-point grounding contact,which has a low cable loss. The grounding apparatus is essentially heldon the functional element by the two holding parts, with the contactspring in this case, but advantageously, carrying out a fixing function,which is possible while retaining a single-point contact.

In order to achieve an improved fixing effect by means of the contactsprings, these are preferably each provided at their free end sectionwith an engagement part, which engages with a corresponding mating piecewhich is provided on the respective associated functional element, inorder to fix the grounding apparatus on the functional element. Therespective engagement part may, for example, be provided simply in theform of a projection which is formed by the contact spring and canengage in a cutout formed in the functional element, or may be a cutoutin which a projection that is formed on the functional element canengage.

In a situation where the holding parts of the respective groundingapparatus are provided with a holding piece, for example a holding pin,which points in the direction of the functional element (insertiondirection) and engages in a corresponding opening in the functionalelement, and the contact springs extend parallel to this holding pieceand their engagement part engages with a corresponding mating piece, thegrounding apparatus is then fixed by the holding piece/mating piececonnection in a direction transversely with respect to the holding piecedirection. The engaged contact springs in this case prevent the holdingpiece from moving out of the mating piece, which is formed in thefunctional element, seen in its longitudinal direction or insertiondirection. This means that the contact springs fix the groundingapparatus in its insertion direction. The contact springs preferablyextend past the respective holding parts and their holding piece,closely adjacent to them, thus achieving particularly compact retention.

The handling apparatus according to the invention for installation of agrounding apparatus according to the invention has an elongated basebody which is in the form of a box and in which a groove which runs inits longitudinal direction is provided, which is open on the outside andinto which a grounding rail of the grounding apparatus can be insertedwith little play. Each longitudinal end section of the base body has aside stop, by which a grounding apparatus (whose grounding rail isinserted into the groove) can be gripped on the longitudinal sides withlittle play, and thus can be centered with respect to handlingapparatus. The groove is advantageously essentially of precisely thesame length as the grounding rail which is to be accommodated in it.

The handling apparatus according to the invention allows a groundingapparatus to be gripped easily and securely, and can thus be fitted morequickly to a functional element of the distribution device.

In order to make it even easier to fit the grounding apparatus, the basebody advantageously has at least one guide tongue, which extendstransversely with respect to the longitudinal direction of the grooveand forwards in the direction of the groove opening, and which has astraight side surface for sliding along a corresponding guide surface ona functional element. An operator therefore just has to place thestraight side surface of the guide tongue on the corresponding guidesurface, with the handling apparatus sliding along the guide surfacetogether with the side surface of the grounding apparatus inserted intoit, in order to fit and to install the grounding apparatus exactly on afunctional element. This largely avoids tilting and other installationfaults which could lead to damage to the parts.

Two guide tongues are preferably provided which are arranged at adistance from one another with respect to the longitudinal direction ofthe base body, and whose straight side surface is formed by their sideend surface. The two straight side surfaces advantageously either faceone another or, in particular, face away from one another, so that theguide tongues which are placed on the corresponding guide surfaces areguided such that they are fixed at the sides, and can thus no longerslide out of their desired guide path at the sides.

The guide tongues are in this case preferably also placed at the top andbottom against corresponding guide surfaces, so that no inadvertentdisplacement is possible in these directions either.

When the grounding apparatus is inserted into the handling apparatus,the guide tongues preferably extend adjacent and parallel to the contactsprings, and preferably at the same time also adjacent and parallel tothe holding parts, in particular to their holding pieces, so that theseparts, which are to be attached and with which contact is to be made, onthe grounding apparatus are arranged close to the guide tongues that areused as guide elements, in order for these parts in particular to keepthe discrepancies from the desired movement path, caused by play, assmall as possible.

According to one embodiment of the invention, the base body has an upperand a lower boundary wall as well as two end walls and a boundary wallon the longitudinal side, and is open on one longitudinal side. Thegroove is in this case open in essentially the same direction as theopen longitudinal side of the base body. This configuration has theadvantage that the parts of the guide apparatus can be partiallyaccommodated in the base body, which is in the form of a box, withoutany problems if required, since the grounding apparatus is inserted intothe groove precisely on that side of the handling apparatus on which thebase body is also open. Furthermore, cutouts can also be provided in theupper boundary wall and in the lower boundary wall of the base body, inwhich components of the grounding apparatus are held, depending on theshape of the grounding apparatus to be accommodated, if they areinserted into the handling apparatus.

The side stops are preferably formed by the two end walls of the basebody, thus avoiding additional stop pieces.

The respective guide tongue is preferably formed from the upper boundarywall of the base body, and the groove is advantageously formed in thelower boundary wall of the base body.

This avoids additional components, so that the handling apparatus has avery compact, and thus low-cost, form. The arrangement (offset withrespect to the height direction of the base body) of the guide tonguesfrom the retaining groove is particularly preferable for a correspondingoffset of the grounding rail and of the holding pieces of the groundingapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in the following text using preferredembodiments and with reference to the drawings, in which:

FIG. 1 shows a distribution device with a grounding device according toone embodiment of the invention, illustrated in perspective, from theside and from above,

FIG. 2 shows the distribution device illustrated in FIG. 1, in aperspective view from the side and from below,

FIG. 3 shows the distribution device according to the invention from theside,

FIG. 4 shows a section view along the distribution device illustrated inFIG. 3, illustrated enlarged,

FIGS. 5 and 6 show the grounding apparatus according to the invention ina perspective view from the side and from above, and from the side andfrom below, respectively,

FIG. 7 shows a safety plug according to one embodiment of the invention,illustrated in perspective from the side and from below,

FIG. 8 shows the safety plug illustrated in FIG. 7, with the protectivecover removed,

FIG. 9 shows the safety plug illustrated in FIG. 8, viewed in adirection from the side and from above,

FIG. 10 shows an enlarged section of the safety plug illustrated in FIG.8, in a side view,

FIG. 11 shows a fitting for the safety plug according to the invention,illustrated in perspective from the side and from below,

FIG. 12 shows the fitting shown in FIG. 11, illustrated in perspectivefrom the side and from above,

FIGS. 13 to 16 show a handling apparatus according to one embodiment ofthe invention, with a grounding apparatus inserted in it, in differentperspective views,

FIG. 17 shows the handling apparatus as shown in FIGS. 13 to 16,illustrated in perspective, without a grounding apparatus inserted,

FIGS. 18 to 21 show exploded illustrations, which are used to show, inperspective form, the insertion of a grounding apparatus according tothe invention into a handling apparatus according to the invention, fromdifferent viewing directions,

FIG. 22 shows an exploded illustration, showing the fitting of agrounding apparatus to a distribution device by means of a handlingapparatus, in a perspective view from the side and from above, and

FIG. 23 shows an illustration, corresponding to the illustration shownin FIG. 22, from a viewing direction from the side and from below.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 to 4 show sections of a distribution device 2 according to theinvention. The distribution device 2 has a grounding device 4 accordingto the invention with a grounding apparatus 6 and a safety plug 8according to one embodiment of the invention. FIGS. 5 and 6 show thegrounding device 6 separately, in each case in a perspective view.

This embodiment of the grounding apparatus 6 has an elongated, flatgrounding rail 10, which in this case is provided as a metal railcomposed of a single bent metal sheet. On its two longitudinal endsections 12, 14, the grounding apparatus 6 has a respective holding part16, 18, which is in this case provided as an angled plastic part, whichhas a first limb 16 a, 18 a and a second limb 16 b, 18 b (see, forexample, FIG. 1).

A retaining slot 16 c, 18 c, into which the grounding rail 10 isinserted, is formed at the free end of one limb 16 a, 18 a of therespective holding part 16, 18. One limb 16 a, 18 a of the respectiveholding part 16, 18 starts from the grounding rail 10 and extendsessentially at right angles to its longitudinal direction upwards, andthe other limb 16 b, 18 b of the respective holding part 16, 18 extendsessentially at right angles to the longitudinal direction of thegrounding rail 10 forwards, in the direction of a functional element 20which is associated with the grounding apparatus 6 and is arranged inthe distribution device 2, together with other functional elements 20,which are designed in a corresponding manner, as will be explained inmore detail later.

The grounding rail 10 is provided as an elongated, flat plate, which isprovided with elongated beads for reinforcement. The grounding rail 10is provided on its longitudinal end sections 12, 14 with elongatedcontact springs 22, 24, which are in the form of tongues and are in thiscase formed integrally with the grounding rail 10, to be precise by thelongitudinal end sections 12, 14 of the grounding rail 10 first of allbeing bent upwards, and then extending forwards with a narrow strip,forming the respective contact spring 22, 24. Each respective contactspring 22, 24 thus has an angled profile (see in particular FIG. 3)which follows the angled profile of the respective holding part 16, 18,with the contact springs 22, 24 in the end extending forwardsessentially parallel to the associated other limb 16 b, 18 b of therespective holding part 16, 18.

The contact springs 22, 24 each pass the associated holding part 16, 18on the outside at the sides, with the respective holding part 16, 18having a retaining slot 16 d, 18 d on the outside at the sides, in whichthe foot of the respective contact spring 22, 24 is held (see, forexample, FIGS. 1 and 2). According to this embodiment, the contactsprings 22, 24 are also each provided with a reinforcing bead. The twocontact springs 22, 24 are also each bent towards one another, that isto say inwards (see, for example, FIG. 1) and can be spread apartresiliently upwards.

As will be explained later in detail, a safety plug 8 is plugged ontothe grounding rail 10. If required, additional safety plugs 8 can alsobe plugged onto the grounding rail 10 alongside the safety plug 8 thatis shown, to be precise up to a maximum of ten safety plugs 8 in thisembodiment. In order to plug each of the safety plugs 8 onto thegrounding rail 10, the safety plugs have a fitting 26, as can be seen inFIG. 4, which is in the form of a bracket and is used as a holdingapparatus, and by means of which the safety plug 8 is clamped onto thegrounding rail 10.

The safety plug 8 also has a contact tongue 28 which extends forwards(see, for example, FIG. 4) and which, as will be explained in moredetail later, can make contact with electrical cables which are providedin the distribution device 2. The fitting 26, which is in the form of abracket, is composed of metal material and is thus electricallyconductive, so that it dissipates an associated overvoltage current tothe grounding rail 10 in the event of an overvoltage between the cableconductors with which the contact tongue 28 makes contact.

The distribution device 2 also has a retaining apparatus 30, which is inthe form of a trough with a trough base 32 and two trough limbs 34, 36,which extend at right angles in the same direction starting from thetrough base 32. Elongated retaining tongues 38 are formed in the troughlimbs 34, 36, extend in the direction in which the trough limbs 34, 36extend, and are arranged in pairs opposite one another. A cutout 40, inwhich an engagement part of a functional element 20 can engage, isformed on the free end section of each retaining tongue 38.

The functional elements 20 are in this case parts in the form of plateswhich are produced, in particular, from nonconductive material, inparticular from plastic material. The functional elements 20 in the formof plates are elongated, with the length of the functional elements 20corresponding approximately to the width of the retaining apparatus 30.On their end faces, the functional elements 20 are provided withlongitudinal grooves 39, such that they can be inserted, on the twolongitudinal end sections, between two retaining tongues 38 of theretaining apparatus 30, such that the retaining tongues 38 can engage inthe end longitudinal grooves in the functional element 20.

At their end of the respective longitudinal groove 39 facing away withrespect to their insertion direction of the retaining apparatus 30, thefunctional elements 20 also have an engagement projection, which, whenthe functional element 20 is completely inserted between two retainingtongues 38, engages in the cutout 40, which is formed at the free end ofeach retaining tongue 38, in order to fix the functional element 20. Theengagement projection is fitted to a resilient engagement arm 42, whichcan be bent outwards and is bent outwards in order to remove thefunctional element 20, in order to remove the engagement projection fromthe cutout 40.

A number of functional elements 20 can thus be held stacked one on topof the other in the retaining apparatus 30, corresponding to the numberof retaining tongues 38 which are arranged opposite one another inpairs.

On its longitudinal side facing away from the trough base 30, eachfunctional element 20 has an elongated contact section 44 in the form ofa contact strip with two or more first connecting points 46 for incomingcables, and with two or more second connecting points 48 for outgoingcables. The first connecting points 46, which are intended for theincoming cables, extend in the longitudinal direction of the contactsection 44 on the upper face of the functional element 20 in a row, andthe connecting points 48 for the outgoing cables extend parallel to thefirst connecting points 46, likewise along the contact section 44, in arow. With regard to the functional elements 20 which are arranged oneabove the other, the row of first connecting points 46 for eachfunctional element 20 is arranged above the row of second connectingpoints 48.

According to this embodiment, ten first connecting points 46 and tensecond connecting points 48 are provided in each case, with eachconnecting point 46, 48 having a double contact point for connection ofin each case two cable wires or cores of a double core cable. A total oftwenty connecting contact points are thus provided for the incomingdouble core cables and twenty connecting contact points are provided forthe outgoing double core cables, per functional element 20. The cableswhich are not shown are introduced at the side into the respectivefunctional element 20, where their cable cores are routed along the coreguides and are electrically connected to the individual connectingcontact points of the connecting points 46, 48.

A retaining cutout 50 (see, for example, FIGS. 1 and 2) is formed oneach longitudinal end section of the elongated contact section 44 ofeach functional element 20, and a holding piece 51 in the form of anengagement pin (see, for example, FIGS. 5 and 6 and FIGS. 15 and 16 aswell) engages in this cutout 50. The holding piece 51 is formed on therespective other limb 16 b, 18 b of the respective holding part 16, 18(see, for example, FIGS. 5 and 6). The grounding apparatus 6 is held andfixed via this pin connection in a direction along the retainingapparatus 30 and transversely with respect to the grounding rail 10.

Each of the contact springs 22, 24 is provided at its respective freeend 22 b, 24 b with a projection which points inwards and which, whenthe grounding apparatus 6 is inserted together with the holding piece 51of the respective holding part 16, 18 into the associated retainingcutout 50 in the associated functional element 20, engages behind theengagement arm 42, which projects slightly outwards at the sides, of theassociated functional element 20. In consequence, the groundingapparatus 6 is also fixed such that it is secured in a direction axiallyparallel to its insertion direction to the respective other angled limb16 b, 18 b and the contact springs 22, 24, and likewise parallel to theretaining tongues 38. At the same time, in this case, the projection onthe contact springs 22, 24 makes contact in a sprung manner with therespectively associated retaining tongue 38 on the electricallyconductive retaining apparatus 30 of the distribution device, so thatthe grounding rail 10 is at ground potential.

Each safety plug 8 has a respective associated first connecting point 46and an associated second connecting point 48, which is arranged oppositea respective first connecting point 46. The contact tongue 28 of eachsafety plug 8 in this case extends between the two rows of connectingpoints 46, 48 (see, for example FIG. 4) in order, as will be explainedfurther below in detail, for each first connecting point 46 to makecontact with the two associated cable cores of an electrical cable whichis connected to them, and for each associated second connecting point 48to make contact with the two associated cable cores of an electricalcable which is connected to them.

Since, as can be seen in particular from FIG. 4, the grounding rail 10is arranged offset downwards in the longitudinal direction of theretaining apparatus 30 with respect to the respectively associatedfunctional element 20, the space 54 between the upper connecting points46 and the lower connecting points 48 in each functional element 20 and,in particular, the respective row of lower connecting points 48(jumpering side) is accessible without any problems for an operator, forjumpering of cable wires/cable cores.

According to this embodiment, the grounding rail 10 is arranged offsetwell downwards with respect to the respectively associated functionalelement 20, such that the grounding rail 10 is arranged approximatelyprecisely at the same level as the upper connecting parts 46 of the nextsubsequent lower functional element 20 (see, for example, FIG. 4), inorder likewise not to block its space 54 between its upper connectingpoints 46 and lower connecting points 48 and, in particular, its lowerconnecting points 48 (jumpering side). The downwards offset of thegrounding rail 10 is likewise chosen to be of such a magnitude that anassociated safety plug 8 can be accommodated without any problems in thefree space which is created above the respective grounding rail 10 bythe offset.

As is shown in FIGS. 7 to 10, a safety plug 8 according to the inventionhas a flat, elongated contact tongue 28, which is provided at its freeend 76 with a longitudinally central gap 78, and on both sides of whichtwo separate conductor tracks 80, 81, 82, 83 are in each case formed andeach make contact with an associated cable core of a double core cablewhich is connected to a first connecting point 46 and of an associated[sic] to a second connecting point 48 of the distribution device 2, whenthe safety plug 8 is connected via its associated grounding device 4 toa distribution device 2.

As can be seen in particular from FIGS. 8 to 10, anovervoltage/overcurrent protection device 84 is arranged at the otherend of the contact tongue 28 and has a surge arrester 85 with a firstelectrode 86, a second electrode 88 and a third electrode 90. The firstelectrode 86 and the second electrode 88 are each connected electricallydirectly to those respective conductor tracks 82, 83 which are intendedto make contact with the respective cable cores of that cable which isconnected to a first connecting point 46 (incoming cable). The tworemaining conductor tracks 80, 81 on the other side of the contacttongue 28, which are intended to make contact with the respective cablecores of that cable which is connected to the associated secondconnecting point 48 (outgoing cable), are connected via theovervoltage/overcurrent protection device 84 to the conductor tracks 82,83. During normal operation, the third electrode 90 does not makeelectrical contact with the first electrode 86 or the second electrode88. In the situation where there is an overvoltage between the two cablecores of the incoming cable which are connected to the respectiveconductor track 82, 83, an electrical contact is formed via the surgearrester 85 between the three electrodes 86, 88, 90 such that anassociated overvoltage current is dissipated to the third electrode 90.The overvoltage current is then passed on via the third electrode 90 tothe grounding rail 10, so that the third electrode 90 acts as agrounding electrode.

In order to pass on an overvoltage current such as this to the groundingrail 10 of the associated grounding apparatus 6 and in order at the sametime to fit the safety plug 8 to this grounding rail 10, this embodimentof the safety plug 8 has a fitting which acts as a holding apparatus andis shown enlarged in FIGS. 11 and 12. The fitting 26 is formed from aconductive material, in particular of metal, and on its lower face hasan insulation-displacement terminal 100, by means of which the fittingis clamped to the third electrode 90, which for this purpose has anattachment 92 in the form of a rod. On its side facing away from theovervoltage/overcurrent protection device 84 and facing away from thecontact tongue 28, the fitting 26 is provided with an attachment part94, which in this case is in the form of a bracket with two limbs. Thebracket limbs 100 a, 100 b of the attachment part 94 can be bent in thedirection at right angles to the longitudinal extent of the contacttongue 28, so that the grounding rail 10 can be clamped in between themin order to secure the safety plug 8. The two clamping limbs 100 a, 100b of the insulation-displacement terminal 100 can be spread apart fromone another, parallel to the surface of the contact tongue 28.

In this case, the fitting 26 is produced from a metal sheet in the formof plate, with the insulation-displacement terminal 100 being partiallystamped out of the associated plate surface and being bent downwards,with the upper clamping limb 94 a of the attachment part 94 being formedfrom a plate section which is bent through 1800 upwards and to the rear,and with the lower clamping limb 94 b of the attachment part 94 beingformed from the remaining plate section.

As can be seen from FIG. 7, a cover 102 in the form of a housing can bepushed over the overvoltage/overcurrent protection device 84 and theassociated end section of the contact tongue 28, and this cover 102 hasa cutout on its upper face, in which the fitting 26 together with itsinsulation-displacement terminal 100 can be held. The cover 102 iscompletely open at the front, so that the contact tongue 28 with itsovervoltage/overcurrent protection device 84 and the fitting 26 fittedto it can be inserted into the cover 102 from this side.

The cover 102 is provided on its side facing the fitting 26, that is tosay in this case on its lower boundary wall 104, with two holding arms106, 108, which are arranged at a distance from one another in thedirection transversely with respect to the direction in which thehousing is plugged on (in this case the longitudinal direction of thecontact tongue 28), and in which a longitudinal groove 106 a, 108 a,which runs in the stated direction in which the cover is plugged on, isformed on the mutually facing inner faces, and adjacent to the lowerboundary wall 104. The holding part 26 engages at the edges in theselongitudinal grooves 106 a, 108 a thus securing it from becomingdetached upwards and downwards.

FIGS. 13 to 16 show a handling apparatus 200 for mounting a groundingapparatus 6 according to the invention on an associated functionalelement 20 according to one embodiment of the invention, with thegrounding apparatus 6 inserted.

FIG. 17 shows the handling apparatus 200 without the grounding apparatusinserted in it. FIGS. 18 to 21 show the handling apparatus 200 and thegrounding apparatus 6 in a state in which the grounding rail 10 of thegrounding apparatus 6 is just inserted into the handling apparatus 200.FIGS. 22 and 23 show how a grounding apparatus 6 is fitted to thedistribution device 2 by means of the handling apparatus 2 according tothe invention.

According to this, the handling apparatus 200 has an elongated base body202 which is in the form of a box and has an upper boundary wall 204, alower boundary wall 206 as well as a boundary wall 208 on thelongitudinal side and two end-face boundary walls 210, 212. The basebody 202 which is in the form of a box is open on the longitudinal sideopposite the boundary wall 208 on the longitudinal side (see, forexample, FIG. 17).

As can be seen in particular from FIG. 17, the base body 202 which is inthe form of a box has a retaining groove 209 which runs in itslongitudinal direction and is formed from the lower boundary wall 206,on its end face facing the open side of the base body 202. The retaininggroove 209 is in this case open in the same direction as the base body202.

The length of the grounding rail 10 is slightly shorter from the lengthof the base body 202 (which is in the form of a box) of the handlingapparatus 200, so that the grounding rail 10 is bounded at its twolongitudinal ends by the end walls 210, 212 of the base body 202, whichis in the form of a box, with little play, when the grounding rail 10 ofthe grounding apparatus 6 is inserted into the retaining groove 209 ofthe handling apparatus 200. The end walls 210, 212 of the base body 200,which is in the form of a box, thus represent side stops for thegrounding apparatus 6 once it has been inserted into the handlingapparatus 200.

Since the holding parts 16, 18, which extend somewhat beyond thegrounding rail 10, would now collide with the side end walls 210, 212 ofthe handling apparatus 200, corresponding cutouts 214, 216 are formed inthe side end walls 210, 212, in each of which cutouts 214, 216 arespective section of the holding parts 16, 18 can be held, as can beseen, for example, from FIGS. 17 to 19. The same applies to the lowerboundary wall 204 and to the upper boundary wall 206 of the base body,in which respective boundary wall cutouts 211, 213; 215, 217 arelikewise formed in order to hold sections of the holding parts 16, 18.

The handling apparatus 200 also has two elongated guide tongues 218,220, each of which is arranged on a longitudinal end section, associatedwith it, of the handling apparatus 200, and which extend forwardsparallel to the opening direction of the retaining groove 209 and to theopen side of the base body 202 which is in the form of a box, and thusalso at right angles to the longitudinal direction of the handlingapparatus 200 and of the grounding apparatus 6 which has been insertedinto it. The two guide tongues 218, 220 are formed from the upperboundary wall 204 of the base body 202; the lateral distance between therespective guide tongue 218, 220 and the associated side end wall 210,212 of the base body is chosen to be sufficiently large to be able tohold the holding parts 16, 18 and the associated contact springs 22, 24between them (see, for example, FIGS. 13 to 15).

The two guide tongues 218, 220 have a respective linear guide surface218 a, 220 a on their outer side surface; the two guide surfaces 218 a,220 a thus face away from one another. The longitudinal distance betweenthese two guide surfaces 218 a, 218 b is slightly less than thelongitudinal distance between the end-face boundary walls of a guideelement 20, so that the handling apparatus 200 can be pushed into thefunctional element 20, guided by its two guide tongues 218, 220 as maybe seen from FIGS. 21 and 22. In this case, the side guide surfaces 218a, 218 b of the two guide tongues 218, 220 slide along an associatedend-face boundary wall of the functional element 20 outside, at thesides.

The grounding apparatus 6 is positioned, as defined by the retaininggroove 209 with respect to the handling apparatus 200 and its guidetongues 218, 220, such that both the holding parts 16, 18 together withtheir attachment pieces 51 as well as the contact springs 22, 24together with their engagement parts 22 b, 24 b, are guided withprecision on the functional element 20 with respect to the correspondingmating pieces. This considerably simplifies the assembly process, thusalso reducing the risk of damage when tilting and incorrect fitting ofgrounding apparatuses 6.

The system comprising the handling apparatus 200 and the groundingapparatus 6 is adapted such that the contact springs 22, 24 extendforwards parallel to the guide tongues 218, 220 and adjacent to themwhen the grounding apparatus 6 is being inserted into the handlingapparatus 200.

In order that the contact springs 220, 218 spring relatively easilyoutwards while the grounding apparatus 6 is being pushed onto thefunctional element 20, ramps 224 are provided on the respectivefunctional element 20, as can be seen in FIGS. 22 and 23, and riseoutwards in the direction in which the grounding apparatus 6 is inserted(see FIGS. 22 and 23). While the grounding apparatus 6 is being pushedon, the contact springs 22, 24 slide over these ramps 224, springingapart to the side, and then slide over the locking arm 42 which isprovided on the respective functional element 20, without there beingany risk of blocking the overall pushing-on movement.

The handling apparatus 200 is preferably provided in the form of aplastic injection-molded part.

Since the grounding apparatus 6 is inserted only loosely from the frontinto the handling apparatus 200, in particular with the grounding rail10 being held only loosely in the retaining groove 209, although thehandling apparatus 200 can exert forces on the grounding apparatus 6 inthe direction in which it is being plugged on, the handling apparatus200 can, however, easily be removed from the grounding apparatus 6,which is then fitted firmly to the functional element 20, that is to sayin this case being plugged in and clamped on, once the mounting of thegrounding apparatus 6 on the functional element 20 has been completed.

1. A grounding apparatus for a distribution device having a functionalelement and a grounding contact point, wherein the distribution deviceincludes at least one functional element defining a front facecomprising a plurality of connecting points extending outwardly from thefunctional element, the grounding apparatus comprising: an elongated,electrically conductive grounding rail having opposed end sections, eachend section provided with a holding part for fitting the grounding railto the functional element of the distribution device, wherein theholding part positions the grounding rail substantially outward of theconnecting points of the functional element when the grounding rail isfitted to the functional element; and an electrically conductive contactspring provided on each of the end sections of the grounding rail, thecontact spring extending outwardly beyond the holding part to makecontact with the grounding contact point on the distribution device. 2.The grounding apparatus as claimed in claim 1, wherein the holding partsare composed of nonconductive, plastic material.
 3. The groundingapparatus as claimed in claim 1 wherein the holding parts each have aholding piece that extends essentially perpendicular to the longitudinalextent of the grounding rail; and wherein the contact springs extendoutwardly from the grounding rail essentially parallel to the holdingpieces.
 4. The grounding apparatus as claimed in claim 3, wherein thegrounding rail is arranged offset with respect to the holding pieces ina direction essentially perpendicular to the longitudinal extent of thegrounding rail.
 5. The grounding apparatus as claimed in claim 1,wherein each contact spring extends outwardly beyond the respectiveholding part relative to the longitudinal extent of the grounding railand is adapted to be spread apart resiliently to make contact with therespective grounding contact point of the distribution device.
 6. Thegrounding apparatus as claimed in claim 1 further comprising at leastone safety plug connected to the grounding rail.
 7. A safety plug foruse with a grounding apparatus of a distribution device having afunctional element, wherein the functional element defines a front facecomprising a plurality of connecting points extending outwardly from thefunctional element and wherein the grounding apparatus is positionedsubstantially outward of the connecting points of the functionalelement, the safety plug comprising: a contact tongue for making contactwith an electrical cable connected to the functional element of thedistribution device; an overvoltage protection device connected to thecontact tongue, the overvoltage protection device having a groundingelectrode with an attachment in the form of a rod through which anovervoltage current is dissipated; and an electrically conductivefitting in electrical contact with the grounding electrode of theovervoltage protection device for connecting the safety plug to thegrounding apparatus, the fitting comprising an insulation-displacementterminal for clamping the fining to the attachment provided on thegrounding electrode; and an attachment part for attaching the fitting tothe grounding apparatus substantially outward of the connecting pointsof the functional element.
 8. The safety plug as claimed in claim 7,wherein the fitting is a clamping part adapted to be clamped to thegrounding apparatus.
 9. A distribution device comprising: an elongatedretaining apparatus; at least one functional element held in theretaining apparatus, each functional element having longitudinal endsections and an elongated contact section with connecting points forconnecting incoming and outgoing electrical cables wherein thefunctional element defines a front face comprising a plurality ofconnecting points extending outwardly from the functional element; atleast one grounding apparatus associated with the at least onefunctional element, the grounding apparatus having a grounding railarranged substantially outward of the connecting points of thefunctional element and parallel to the elongated contact section of theassociated functional element and the grounding apparatus having holdingparts on opposed ends of the grounding rail for receiving thelongitudinal end sections of the functional element; and at least onesafety plug associated with the at least one grounding apparatus, thesafety plug having a contact tongue extending in the direction of thefunctional element for connecting the safety plug to the grounding railto make contact with the electrical cables.
 10. The distribution deviceas claimed in claim 9, wherein the grounding rail of each groundingapparatus is arranged offset with respect to the associated functionalelement in the longitudinal direction of the retaining apparatus. 11.The distribution device as claimed in claim 9 wherein the connectingpoints are arranged along the elongated contact section of therespective functional element and are subdivided into a row of firstconnecting points for the incoming electrical cables and a row of secondconnecting points for the outgoing electrical cables; and wherein thegrounding rail of the associated grounding apparatus is arrangedadjacent to the row of second connecting points.
 12. The distributiondevice as claimed in claim 9 wherein the retaining apparatus is in theform of an elongated, electrically conductive retaining trough with atrough base and two trough limbs in which elongated, retaining tonguesare formed and between which the respective functional element isinserted; and wherein the grounding apparatus comprises contact springsthat make contact to the associated functional element in a sprungmanner with the retaining tongues to produce an electrical contact. 13.The distribution device as claimed in claim 12, wherein the contactsprings on the grounding rail of the grounding apparatus are providedwith an engagement part for engaging a corresponding mating pieceprovided on the associated functional element to fix the groundingapparatus on the functional element.
 14. A handling apparatus forinstalling a grounding apparatus of a distribution device having afunctional element, wherein the distribution device includes at leastone functional element defining a front face comprising a plurality ofconnect of points extending outwardly from the functional element thehandling apparatus comprising: an elongated base body in the form of abox and having a retaining groove extending in a longitudinal direction,the base body open on one side for receiving a grounding rail of thegrounding apparatus within the retaining groove and having a side stopthat centers the grounding apparatus with the grounding rail insertedinto the retaining groove relative to the handling apparatus; whereinthe grounding rail is adapted to be positioned substantially outward ofthe connecting points of the functional element when the handlingapparatus is installed on the distribution device.
 15. The handlingapparatus as claimed in claim 14, wherein the base body has at least oneguide tongue that extends transversely with respect to the longitudinaldirection of the retaining groove and a side surface for sliding along acorresponding guide surface on the functional element.
 16. The handlingapparatus as claimed in claim 15, further comprising a pair of guidetongues that are arranged at a predetermined distance from one anotherwith respect to the longitudinal direction of the retaining groove. 17.The handling apparatus as claimed in claim 15 wherein the base body hasan upper boundary wall, a lower boundary wall, two end walls and aboundary wall that extends in the longitudinal direction of theretaining groove such that the base body is open on one side; andwherein to retaining groove is essentially open in the same direction asthe open side of the base body.
 18. The handling apparatus as claimed inclaim 17, wherein side stops are formed by the two end walls of the basebody.
 19. The handling apparatus as claimed in claim 17 wherein eachguide tongue is formed from the upper boundary wall of the base body andwherein the retaining groove is formed in the lower boundary wall of thebase body.